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Washington — First lady Jill Biden tested positive for COVID-19 on Wednesday with an apparent “rebound” infection and will return to isolation, her office said in a statement.

“The First Lady has experienced no reemergence of symptoms, and will remain in Delaware where she has reinitiated isolation procedures,” communications director Kelsey Donohue said in a statement. “The White House Medical Unit has conducted contact tracing and close contacts have been notified.”

The first lady first tested positive last week and was in isolation in South Carolina for five days. She experienced mild, cold-like symptoms and was treated with the antiviral drug Paxlovid, which has been linked to rebound infections. She joined President Biden in Delaware on Sunday following two negative tests.

The president also experienced a rebound case last month, when he tested positive again several days after leaving isolation. The president returned on Wednesday to the White House, where he is set to announce his plan to cancel up to $20,000 in debt for millions of Americans with federal student loans.

Mr. Biden tested negative for COVID-19 on Wednesday morning, a White House official said. 

“Consistent with CDC guidance because he is a close contact of the First Lady, he will mask for 10 days when indoors and in close proximity to others,” the official said. “We will also keep the President’s testing cadence increased and continue to report those results.”